Initial backend for metrics in Observatory

runtime/vm/service.cc

 // Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "vm/service.h"
 
 #include "include/dart_api.h"
 #include "platform/globals.h"
 
 #include "vm/compiler.h"
@@ skipping 1562 matching lines @@
   ASSERT(ring != NULL);
   intptr_t id = -1;
   if (!GetIntegerId(arg, &id)) {
     *error = true;
     return Instance::null();
   }
   return ring->GetObjectForId(id);
 }
 
 
+static RawClass* GetMetricsClass(Isolate* isolate) {
+  const Library& prof_lib =
+      Library::Handle(isolate, Library::ProfilerLibrary());
+  ASSERT(!prof_lib.IsNull());
+  const String& metrics_cls_name =
+      String::Handle(isolate, String::New("Metrics"));
+  ASSERT(!metrics_cls_name.IsNull());
+  const Class& metrics_cls =
+      Class::Handle(isolate, prof_lib.LookupClass(metrics_cls_name));
+  ASSERT(!metrics_cls.IsNull());
+  return metrics_cls.raw();
+}
+
+
+static bool HandleMetricsList(Isolate* isolate, JSONStream* js) {
+  const Class& metrics_cls = Class::Handle(isolate, GetMetricsClass(isolate));
+  const String& print_metrics_name =
+      String::Handle(String::New("_printMetrics"));
+  ASSERT(!print_metrics_name.IsNull());
+  const Function& print_metrics = Function::Handle(
+      isolate,
+      metrics_cls.LookupStaticFunctionAllowPrivate(print_metrics_name));
+  ASSERT(!print_metrics.IsNull());
+  const Array& args = Object::empty_array();
+  const Object& result =
+      Object::Handle(isolate, DartEntry::InvokeFunction(print_metrics, args));
+  ASSERT(!result.IsNull());
+  ASSERT(result.IsString());
+  TextBuffer* buffer = js->buffer();
+  buffer->AddString(String::Cast(result).ToCString());
+  return true;
+}
+
+
+static bool HandleMetric(Isolate* isolate, JSONStream* js, const char* id) {
+  const Class& metrics_cls = Class::Handle(isolate, GetMetricsClass(isolate));
+  const String& print_metric_name =
+      String::Handle(String::New("_printMetric"));
+  ASSERT(!print_metric_name.IsNull());
+  const Function& print_metric = Function::Handle(
+      isolate,
+      metrics_cls.LookupStaticFunctionAllowPrivate(print_metric_name));
+  ASSERT(!print_metric.IsNull());
+  const String& arg0 = String::Handle(String::New(id));
+  ASSERT(!arg0.IsNull());
+  const Array& args = Array::Handle(Array::New(1));
+  ASSERT(!args.IsNull());
+  args.SetAt(0, arg0);
+  const Object& result =
+      Object::Handle(isolate, DartEntry::InvokeFunction(print_metric, args));
+  ASSERT(!result.IsNull());

[turnidge, 2014/07/30 19:15:00]

You should handle null here.  The _printMetric function can return null.

[Cutch, 2014/07/30 21:55:04]

Excellent catch.

+  ASSERT(result.IsString());
+  TextBuffer* buffer = js->buffer();
+  buffer->AddString(String::Cast(result).ToCString());
+  return true;
+}
+
+
+static bool HandleMetrics(Isolate* isolate, JSONStream* js) {
+  if (js->num_arguments() == 1) {
+    return HandleMetricsList(isolate, js);
+  }
+  if (js->num_arguments() > 2) {
+    PrintError(js, "Command too long");
+    return true;
+  }
+  const char* arg = js->GetArgument(1);
+  return HandleMetric(isolate, js, arg);
+}
+
+
 static bool HandleObjects(Isolate* isolate, JSONStream* js) {
   REQUIRE_COLLECTION_ID("objects");
   if (js->num_arguments() < 2) {
     PrintError(js, "expected at least 2 arguments but found %" Pd "\n",
                js->num_arguments());
     return true;
   }
   const char* arg = js->GetArgument(1);
 
   // Handle special objects first.
@@ skipping 503 matching lines @@
   { "_echo", HandleIsolateEcho },
   { "", HandleIsolate },
   { "address", HandleAddress },
   { "allocationprofile", HandleAllocationProfile },
   { "classes", HandleClasses },
   { "code", HandleCode },
   { "coverage", HandleCoverage },
   { "debug", HandleDebug },
   { "heapmap", HandleHeapMap },
   { "libraries", HandleLibraries },
+  { "metrics", HandleMetrics },

[turnidge, 2014/07/30 19:15:00]

Will we ever want to have per-vm metrics instead of per-isolate metrics?  Just
curious.  This is ok for now.

[Cutch, 2014/07/30 21:55:04]

Yes, for example, the number of isolates could be a metric reported by the VM.

These will be implemented in C++ though.

   { "objects", HandleObjects },
   { "profile", HandleProfile },
   { "scripts", HandleScripts },
   { "stacktrace", HandleStackTrace },
   { "typearguments", HandleTypeArguments },
 };
 
 
 static IsolateMessageHandler FindIsolateMessageHandler(const char* command) {
   intptr_t num_message_handlers = sizeof(isolate_handlers) /
@@ skipping 325 matching lines @@
   while (current != NULL) {
     if (strcmp(name, current->name()) == 0) {
       return current;
     }
     current = current->next();
   }
   return NULL;
 }
 
 }  // namespace dart